/* ===================

AX2E (AXESCON XACML 2.0 Engine) is the Java authorization engine, which implements OASIS XACML 2.0 standard.
Copyright (C) 2007 AXESCON LLC

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA


Contact: AXESCON LLC - info{at}axescon.com

 =================== */
package axescon.xacml.engine.fn;

import axescon.xacml.api.*;
import axescon.xacml.model.policy.AttributeValue;

import java.lang.reflect.Array;

/**
 * @author Date: Sep 28, 2005
 *         Responsibilities: implements "type-bag" functions from
 *         see axescon.xacml 2.0 spec ch. A.3.10 Bag functions
 */
public class FnBag extends AbstractFn implements Fn {

    public int getArgTypeListLength() {
        return 1;
    }

    public int getMaxArgListLength() {
        return -1;
    }

    public int getMinArgListLength() {
        return 0;
    }

    public Liquid exec(Liquid[] args) throws ExpressionEvalIndeterminateException {
        if (args == null || args.length == 0) return Liquid.newEmptyBag();

        // at this point we know that args are not empty
        AttributeValue[] ret = (AttributeValue[])Array.newInstance(args[0].getSingularUnsafe().getClass(),args.length);
        for (int i = 0; i < args.length; i++) {
            ret[i] = args[i].getSingular();
        }
        return new Liquid(ret);
    }


    public FnBag() {
    }

    public Class getReturnDataType() {
        return super.getReturnDataTypeBag(0);
    }

}
